Scientists at Caltech and USC have discovered a way to speed up the slow part of the chemical reaction that ultimately helps the earth to safely lock away, or sequester, carbon dioxide into the ocean. Simply adding a common enzyme to the mix, the researchers have found, can make that rate-limiting part of the process go 500 times faster.

…

On paper, the reaction is fairly straightforward: Water plus carbon dioxide plus calcium carbonate equals dissolved calcium and bicarbonate ions in water. In practice, it is complex. “Somehow, calcium carbonate decides to spontaneously slice itself in half. But what is the actual chemical path that reaction takes?” Adkins says.

Studying the process with a secondary ion mass spectrometer (which analyzes the surface of a solid by bombarding it with a beam of ions) and a cavity ringdown spectrometer (which analyzes the 13C/12C ratio in solution), Subhas discovered that the slow part of the reaction is the conversion of carbon dioxide and water to carbonic acid.

“This reaction has been overlooked,” Subhas says. “The slow step is making and breaking carbon-oxygen bonds. They don’t like to break; they’re stable forms.”

Armed with this knowledge, the team added the enzyme carbonic anhydrase — which helps maintain the pH balance of blood in humans and other animals — and were able to speed up the reaction by orders of magnitude.

Bacterial cells in carbon-rich media (purple and blue) grow twice as big as those in carbon-poor media (green). New research shows they can grow big, however, only if they can make fats with the carbon.

Fat (lipids) limits how big bacterial cells can be. “If you prevent cells from making fat, they’re smaller, and if you give them extra fat or allow them to make more fat, they get bigger,” said Levin, professor of biology in Arts & Sciences. “Fat makes cells fat.”

“If we hit the cells with an antibiotic that targets fatty-acid synthesis, we really saw a significant drop in cell size” Vadia said.

Also, by turning up FadR, a transcription factor that activates expression of the fatty-acid synthesis genes, the cells got bigger.

“It doesn’t seem to matter what the lipids are, really,” Levin said, “provided you have enough of them. We found we could give the cells oleic acid, a fat found in avocados and olive oil, to supplement diminished fatty-acid synthesis and as long as the added fatty acid got into the membrane, the cells could recover.”

In regions with more rainfall historically, soil microbes were found to respire twice as much carbon to the atmosphere as microbes from drier regions. Scientists determined that this was because the microbes responded differently to change: Those from the wettest areas were four times as sensitive to shifts in moisture as their counterparts from the driest areas.

“Because microbes are small and enormously diverse, we have this idea that when the environment changes, microbes can rapidly move around or shift local abundances to track that environmental change,” Hawkes said. “We discovered, however, that soil microbes and their functions are highly resistant to change. Resistance to environmental change matters because it means that previous local conditions will constrain how ecosystems function when faced with a shift in climate.”

the rate limiting step in SOC mineralization is abiotic (physical rather than biological).

that mineralization of SOC may be a two-stage process: firstly, non-bioavailable forms are converted abiologically to bioavailable forms, which, only then, undergo a second process, biological mineralization.

Compounds we should be trying to keep in the soil profile doing good, and not in aquifers or waterways creating algal blooms, like we really need to with this recently discovered underground molten lake the size of Mexico!

Add 1.5% biochar to a 3.5% (0-100mm sampled) soil organic carbon soil, wait 9 years and it begins to positively prime. Clearly they didn’t add enough to reach a tipping point faster, or depending on your perspective and availability, adding biochar to low carbon soils is a long-term investment. I assume it was surface applied as the study is paywalled.

The ocean sequesters massive amounts of carbon in the form of “dissolved organic matter,” and new research explains how an ancient group of cells in the dark ocean wrings the last bit of energy from carbon molecules resistant to breakdown.

A look at genomes from SAR202 bacterioplankton found oxidative enzymes and other important families of enzymes that indicate SAR202 may facilitate the last stages of breakdown before the dissolved oxygen matter, or DOM, reaches a “refractory” state that fends off further decomposition.

Zach Landry, an OSU graduate student and first author of the study, named SAR202 “Monstromaria” from the Latin term for “sea monster.”

For the first time, researchers have shown that cultured picocyanobacteria, Synechococcus and Prochlorococcus, found in the open ocean release fluorescent components that closely match these typical fluorescent signals found in oceanic environments.

“Two genus of picocyanobacteria – Synechococus and Prochlorocccos – are the most abundant carbon fixers in the ocean.” said Chen. His lab maintains a collection of marine cyanobacteria and cyanoviruses. Some of these isolates were used in this study.

“When you sail on the blue ocean, a lot of picocyanbacteria are working there,” said Gonsior.” They turn carbon dioxide into organic carbon and are likely responsible for some of the deep ocean color coming from organic matter.”